批量导出表数据到CSV文件

Posted 2020-09-12 clnchanpin

需求：把oracle数据库中符合条件的N多表。导出成csv文本文件。并以表名.csv为文件名称存放。

实现：通过存储过程中UTL_FILE函数来实现。导出的csv文件放入提前创建好的directory中。

用法：使用下面命令数据预运行的SQL脚本

SELECT ‘EXEC sql_to_csv(‘‘select * from ‘ ||T.TABLE_NAME ||

‘‘‘,‘‘OUT_PUT_CSV‘‘‘ || ‘,‘‘ODS_MDS.‘ || T.TABLE_NAME ||
‘.csv‘‘);‘
FROM user_TABLES T

脚本说明：sql_to_csv 存储过程名。out_put_csv数据库文件夹名称；ODS_MDS提前定义的schema名称；

存储过程代码例如以下:

CREATE OR REPLACE PROCEDURE CHENQY.SQL_TO_CSV
(
 P_QUERY IN VARCHAR2, -- PLSQL文
 P_DIR IN VARCHAR2, -- 导出的文件放置文件夹
 P_FILENAME IN VARCHAR2 -- CSV名
 )
 IS
  L_OUTPUT UTL_FILE.FILE_TYPE;
  L_THECURSOR INTEGER DEFAULT DBMS_SQL.OPEN_CURSOR;
  L_COLUMNVALUE VARCHAR2(4000);
  L_STATUS INTEGER;
  L_COLCNT NUMBER := 0;
  L_SEPARATOR VARCHAR2(1);
  L_DESCTBL DBMS_SQL.DESC_TAB;
  P_MAX_LINESIZE NUMBER := 32000;
BEGIN
  --OPEN FILE
  L_OUTPUT := UTL_FILE.FOPEN(P_DIR, P_FILENAME, ‘W‘, P_MAX_LINESIZE);
  --DEFINE DATE FORMAT
  EXECUTE IMMEDIATE ‘ALTER SESSION SET NLS_DATE_FORMAT=‘‘YYYY-MM-DD HH24:MI:SS‘‘‘;
  --OPEN CURSOR
  DBMS_SQL.PARSE(L_THECURSOR, P_QUERY, DBMS_SQL.NATIVE);
  DBMS_SQL.DESCRIBE_COLUMNS(L_THECURSOR, L_COLCNT, L_DESCTBL);
  --DUMP TABLE COLUMN NAME
  FOR I IN 1 .. L_COLCNT LOOP
    UTL_FILE.PUT(L_OUTPUT,L_SEPARATOR || ‘"‘ || L_DESCTBL(I).COL_NAME || ‘"‘); --输出表字段
    DBMS_SQL.DEFINE_COLUMN(L_THECURSOR, I, L_COLUMNVALUE, 4000);
    L_SEPARATOR := ‘,‘;
  END LOOP;
  UTL_FILE.NEW_LINE(L_OUTPUT); --输出表字段
  --EXECUTE THE QUERY STATEMENT
  L_STATUS := DBMS_SQL.EXECUTE(L_THECURSOR);
 
  --DUMP TABLE COLUMN VALUE
  WHILE (DBMS_SQL.FETCH_ROWS(L_THECURSOR) > 0) LOOP
    L_SEPARATOR := ‘‘;
    FOR I IN 1 .. L_COLCNT LOOP
      DBMS_SQL.COLUMN_VALUE(L_THECURSOR, I, L_COLUMNVALUE);
      UTL_FILE.PUT(L_OUTPUT,
                   L_SEPARATOR || ‘"‘ ||
                   TRIM(BOTH ‘ ‘ FROM REPLACE(L_COLUMNVALUE, ‘"‘, ‘""‘)) || ‘"‘);
      L_SEPARATOR := ‘,‘;
    END LOOP;
    UTL_FILE.NEW_LINE(L_OUTPUT);
  END LOOP;
  --CLOSE CURSOR
  DBMS_SQL.CLOSE_CURSOR(L_THECURSOR);
  --CLOSE FILE
  UTL_FILE.FCLOSE(L_OUTPUT);
EXCEPTION
  WHEN OTHERS THEN
    RAISE;
END;
 
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